1. Field of the Invention
The present invention relates to a rotary type ultralow temperature refrigerant supply apparatus, and, more particularly, to a rotary type ultralow temperature refrigerant supply apparatus that is capable of separately forcibly circulating a liquid-phase ultralow temperature refrigerant supplied from a refrigeration system and a gas-phase ultralow temperature refrigerant obtained through the evaporation of the liquid-phase ultralow temperature refrigerant by an evaporator.
2. Description of the Related Art
Generally, super conductivity is called a phenomenon in which the electric resistance of a specific material reaches 0 under a certain temperature. A super conductor causes super conductivity at an ultralow temperature state in which the temperature is normally very low.
In particular, a super conductive rotor formed by winding a super conductor in the shape of a coil is used in electric generator and electric motor fields using such a super conductor. For the super conductivity, it is essentially required for the super conductive rotor to be maintained in an ultralow temperature state. Consequently, a cooling apparatus is also essentially required.
A rotary type ultralow temperature refrigerant supply apparatus, which is an example of the cooling apparatus, is an apparatus that supplies an ultralow temperature refrigerant from a refrigeration system in a stoppage state to a super conductive rotor in a rotation state. As shown in FIG. 3, a conventional rotary type ultralow temperature refrigerant supply apparatus 300 is installed between a super conductive rotor 200 including an evaporator 202 formed in a rotary shaft 201 and a plurality of super conductive coils 203 coupled to the outer circumference of the rotary shaft 201 and a refrigeration system 100 configured to supply an ultralow temperature refrigerant for supplying the ultralow temperature refrigerant into the evaporator 201 formed in the super conductive rotor 200 and discharging the ultralow temperature refrigerant from the evaporator 201 while maintaining the heat insulation state of the ultralow temperature refrigerant.
In particular, the conventional rotary type ultralow temperature refrigerant supply apparatus 300 as described above includes a refrigerant introduction pipe 301, a heat insulation casing 302 configured to thermally insulate the refrigerant introduction pipe 301 in a vacuum state, and a magnetic fluid seal 303 disposed between the heat insulation casing 302 in a stoppage state and the super conductive rotor 200 in a rotation state for sealing a gas-phase ultralow temperature refrigerant.
Consequently, an ultralow temperature refrigerant liquefied by the refrigeration system 100 is supplied into the evaporator 202 in the super conductive rotor 200 along the refrigerant introduction pipe 301 by virtue of gravity. The liquid-phase ultralow temperature refrigerant is evaporated, by the evaporator 202, into a gas-phase ultralow temperature refrigerant. The gas-phase ultralow temperature refrigerant moves to the refrigeration system 100 along the refrigerant introduction pipe 301. At this time, the liquid-phase ultralow temperature refrigerant and the gas-phase ultralow temperature refrigerant flow along the refrigerant introduction pipe 301 in opposite directions.
However, such a natural circulation type refrigerant supply apparatus supplies the liquid-phase ultralow temperature refrigerant only to a position lower than the refrigerant introduction pipe due to its characteristic using gravity. For this reason, the diameter of the super conductive rotor 200 is increased, and therefore, the diameter of the evaporator is increased. In this structure, the distance between a liquid contact part contacting the refrigerant and a liquid non-contact part not contacting the refrigerant in the evaporator increases, with the result that it is not possible to obtain a uniform cooling property of the super conductive rotor.